Chemical hazards occur when chemicals present in food are at levels harmful to humans. Contamination may through different routes, such as the environment (air, soil and water), during manufacturing processes and addition of food additives. It can occur naturally, accidently or even deliberately. The most common chemical hazards in the food industry include: mycotoxins, marine and natural toxins, cleaning chemicals, antibiotics, pesticides, food additives, chemicals produced during processing and environmental contaminants.
Chemical contamination can be a deliberate act for financial gain. There have been numerous cases where milk has been adulterated with harmful chemicals. In 2008 melamine was used in China to falsify protein levels in milk for infants, which resulted in 300,000 cases of illness and 6 deaths. The Indian Food Standards Authority also conducted tests in 2012 and found nearly 70 percent of milk was adulterated with chemicals including fertiliser, hydrogen peroxide and detergent. But the most interesting case was in China in 2016 where food was deliberately adulterated in 35 Chinese restaurants with opium powder to hook customers.
Mycotoxins are a group of naturally occurring chemicals produced by certain moulds, such as Aspergillus flavus and Penicullium expansum. They can grow on a wide range of foods, including cereals, nuts, peanuts, spices, and fruit (apples and pears). Mycotoxins can also be found in livestock due to contaminated feed. These toxins can cause vomiting, diarrhoea, kidney damage, suppression of the immune system and death. In 2004, 125 Kenyans died after eating maize contaminated with aflatoxin due to early harvesting, failure to treat the crop with fungicides and insufficient drying before storage.
Pesticides generally include insecticides, fungicides and herbicides. A major health concern with pesticides is that they can accumulate in the food chain and contaminate the environment. Food contaminated with pesticides have notoriously been implicated in deadly outbreaks of food poisoning in recent years. Cooking oil stored in bottles previously used to store pesticide killed 23 children in India in 2013 and sweets contaminated with pesticide kill 23 people in Pakistan in 2016.
Deadly Marine Toxins
Japanese Pufferfish (Fugu) is well known for its lethal poison. Tetrodotoxin is a powerful marine toxin that is up to 1,200 times more poisonous than cyanide. A small dose can cause tingling and numbness around the mouth, and a larger dose can cause respiratory failure, extensive paralysis and even death. Incidents of poisonings usually occur when fish is prepared by uncertified handlers. Not surprisingly, the sale of Fugu for consumption in Europe is banned.
Antibiotics can be a problem as overuse can increase the risk that harmful bacteria will become resistance to them. Antimicrobial resistance is responsible for over 25,000 deaths in Europe annually. Contamination can occur in many different ways. It can happened when manure is spread in the environment or when faecal matter contaminates meat products during slaughter. Resistant bacteria living in water can contaminate vegetables, fruit and shellfish. Cross contamination can also spread AMR bacteria from one food to another.
Environmental contaminants may be present in the environment naturally or introduced by human activities deliberately or accidently. Naturally occurring chemicals include Arsenic, Cadmium, Lead and Mercury. Rice contains 10-20 times more arsenic than other crops because it is grown in water and makes easier for chemical to be absorbed into rice grains. Arsenic can increase the risk of illnesses, including cancer. Methyl mercury is organic compound created by bacterial action in an aquatic environment due to natural and industrial sources of mercury. Marlin, Shark and Swordfish higher concentrations of mercury than other species of fish. Mercury poisoning is highly toxic due its ability to damage the nervous system.
Harmful chemicals created during food processing
Processing foodstuffs can create harmful chemicals in food. Acrylamide is a chemical with the potential to cause cancer and is formed by a reaction between amino acids and sugars during the cooking process. It typically occurs when foods high in starch are fried, baked or roasted at temperatures over 120OC. Acrylamide is found in common food products such a roast potatoes and root vegetables, chips, crisp, toast, cereals, biscuits, cereals and coffee.
Chemical contamination is discussed on all our food safety and HACCP courses. We offer courses at levels 2, 3 and 4. Explore our website to find out more. We also offer onsite courses at your premises for a reasonable price, and regularly deliver courses in London, Milton Keynes and the Home Counties.